JP2015140972A - heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger composed of a honeycomb structure, in which the honeycomb structure has a new function, and new fluid flow can be provided.SOLUTION: A heat exchanger 1000 composed of a honeycomb structure, has a first space 41 composed of a first flow channel, and a pair of connection holes 30 extended from a first opening 31 to a second opening 32, and a second space 42 composed of a second flow channel partitioned from the first flow channel by an inner wall 50. A pair of virtual lines connecting middle points of short sides at a side far from sealing portions, of the first opening 31 and the second opening 32 are straight lines in parallel with each other. A pair of second virtual lines connecting middle points of short sides at a side close to the sealing portions of the first opening and the second opening are straight lines vertical to a first side wall and intersecting the first virtual lines in the first side wall or a second side wall.

Description

  The present invention relates to a heat exchanger composed of a ceramic honeycomb structure.

  The honeycomb structure is composed of a large number of flow paths whose interior is partitioned by inner walls. When a fluid passes through the flow path of the honeycomb structure, heat, a substance, and the like can be moved through the inner wall, so that it is widely used as a heat exchanger.

Among them, ceramic honeycomb structures are excellent in heat resistance and chemical stability, and are therefore used in heat exchangers used under high temperature and corrosive environments.
Patent Document 1 is a high-temperature heat exchanger including an element made of a porous silicon carbide sintered body that exchanges heat between a fluid flowing through the inside and a fluid existing outside. A high temperature heat exchanger is described in which the element is a honeycomb structure having a plurality of cells extending in the longitudinal direction.
It is described that a heat exchanger using such a honeycomb structure is excellent in strength and can efficiently exchange heat between fluids having different temperatures.

JP-A-6-345555

The ceramic is used in the honeycomb structure because the atoms constituting the material are strongly bonded by a covalent bond and have high strength, heat resistance, and corrosion resistance. On the other hand, the ceramic material becomes a hard and brittle material due to such a feature of the covalent bond.
For this reason, the ceramic honeycomb structure is manufactured by a simple forming method such as extrusion, and has a simple shape in which flow paths are arranged in one direction. Because of this shape, the parts to which the honeycomb structure is applied are designed on the assumption that the flow paths are aligned in one direction, and the degree of freedom in designing a heat exchanger using the honeycomb structure is small.

  The present invention exceeds the application range of such a conventional heat exchanger composed of a ceramic honeycomb structure, and has a honeycomb structure that can give a new function to the honeycomb structure and handle a new fluid flow. An object is to provide a heat exchanger.

  The heat exchanger of the present invention for solving the above-mentioned problems is a heat exchanger comprising a ceramic honeycomb structure having at least a first end face, a second end face, a first side wall, and a second side wall, The honeycomb structure has a first flow path partitioned by an inner wall and extending from the first end face to the second end face and sealed by sealing portions, and a second flow path open at both ends. The first flow path and the second flow path each constitute a row aligned from the first side wall toward the second side wall, and heat exchange configured as alternately arranged rows In the vessel, the honeycomb structure includes the first flow path, and a rectangular first opening formed on the first end face side of the first side wall and on the second end face side of the second side wall, respectively. Extends to a rectangular second opening formed in the inner wall A first space comprising a pair of connection holes, and a second space comprising a first flow path and a second flow path separated by the inner wall, and the first opening And the pair of first imaginary lines connecting the midpoints of the short sides on the side far from the sealing portion of the second opening are straight lines parallel to each other, and the first opening and the second opening A pair of second imaginary lines connecting the midpoints of the short sides closer to the sealing portion are perpendicular to the first side wall and intersect the first imaginary line in the first side wall or the second side wall. It is a straight line.

  According to the heat exchanger composed of the honeycomb structure of the present invention, unlike the conventional honeycomb structure in which the flow path extends in one direction, a fluid flow can be created in a direction crossing the honeycomb structure. Further, in such a honeycomb structure, since the first opening and the second opening are formed inside the first opening, not only the first flow channel located at the outermost periphery but also the inner first A fluid flow can also be created in one channel. In addition, since the second opening is formed at a position facing the first opening, the fluid can be moved with the first flow path inside the second opening in the shortest distance, and efficiently. A heat exchanger through which a fluid can flow can be provided.

In addition, since the heat exchanger of the present invention is made of ceramic and has heat resistance and corrosion resistance and high strength, it can handle a fluid even in a severe environment such as a high temperature environment or a corrosive environment.
Furthermore, in the heat exchanger according to the present invention, the first space has the sealing portions on the first end surface and the second end surface, respectively, so that the fluid from the first end surface and the second end surface side is in the first space. Intrusion can be prevented. Furthermore, since the first space is separated from the second space by the inner wall, the fluid flowing in the first space (first fluid) and the fluid flowing in the second space (second fluid) are in direct contact with each other. Absent. For this reason, functions, such as heat transfer and filtration, can be held in the inner wall.

  Since the heat exchanger of the present invention has a pair of connection holes in the first space, the pair of connection holes can serve as an inlet and an outlet for the fluid flowing in the first space. By providing an inlet and an outlet with a pair of connection holes in the first space, the fluid flowing in the first space (first fluid) can be used continuously.

  In addition, by having a pair of connection holes in the first space, there is an effect of increasing the amount of heat passing through the inner wall. The amount of heat passing through the inner wall that separates the first space and the second space is proportional to the temperature difference between the first space and the second space. By forming a flow from the inlet to the outlet in the fluid flowing through the first space, a new first fluid can be constantly supplied, and a temperature difference can be generated on the inner wall to increase the amount of heat that moves.

  The heat exchanger according to the present invention has the connection holes on the first and second side walls, respectively, so that the distance that the first fluid that connects the inlet and the outlet flows is equal regardless of the first flow path. can do. For this reason, since the 1st fluid can be spread over the whole inner wall, the heat exchanger which can perform heat transfer or mass transfer efficiently can be provided.

  In the heat exchanger according to the present invention, the first space and the second space face the first sidewall or the second sidewall alternately so that the flow in the direction crossing the flow path of the honeycomb structure is performed. They can be arranged in alternate flow paths. For this reason, the area of the inner wall that separates the fluid flowing along the second flow path (second fluid) and the first fluid flowing in the direction crossing the flow path (first fluid) can be increased.

  In the heat exchanger of the present invention, the shape of the first opening and the second opening is a rectangle that is long in the direction of the flow path. Since the opening is the first opening and the second opening, the fluid can be efficiently put in and out of the elongated channel while reducing the pressure loss.

  In the heat exchanger of the present invention, the pair of first imaginary lines connecting the midpoints of the short sides on the side far from the sealing portions of the first opening and the second opening are straight lines parallel to each other. A pair of second imaginary lines connecting the midpoints of the short sides of the opening and the second opening close to the sealing portion are perpendicular to the first side wall and the first side wall or the second side wall Since it is a straight line intersecting with one imaginary line, the cross section in the depth direction along the flow path of the connection hole formed by the first opening and the second opening is close to the sealing portion of the first opening. It becomes a right triangle with a right angle. The closer the connection hole is to the bottom, the narrower it becomes, so it is difficult to form a portion where the fluid stagnates at the bottom of the connection hole, so that the fluid can flow efficiently. In addition, since the pair of second imaginary lines connecting the midpoints of the short sides closer to the sealing portion of the first opening and the second opening are perpendicular to the first side wall, the connection hole is connected to the first end. It is possible to approach the first end portion or the second end portion, and it is possible to reduce the useless first flow path in which the fluid does not flow easily.

Furthermore, the honeycomb structure of the present invention desirably has the following aspect.
(1) The inclination angle θ of the first imaginary line with respect to the first side wall or the second side wall is 35 degrees to 50 degrees.
When the inclination angle θ is 50 degrees or less, the pressure loss of the first fluid can be reduced, and when the inclination angle is 35 degrees or more, the length of the flow path can be increased and the heat exchange efficiency can be increased. Can be increased.

(2) The heat exchanger according to claim 2 or 2, wherein the connection hole is formed by stacking the second openings having five or more layers.
The heat exchanger of the present invention can supply the first fluid to the sixth flow path counted from the first side wall side by stacking the second openings of five layers or more. By adopting such a configuration, the area of the inner wall that separates the first space and the second space can be increased.

(3) In the connection hole, the second openings having ten or more layers are stacked.
The heat exchanger of the present invention can supply the first fluid to the eleventh channel counted from the first side wall side by stacking the second openings of 10 layers or more. With such a configuration, the area of the inner wall separating the first space and the second space can be further increased.

(4) The ceramic is made of silicon carbide, silicon-impregnated silicon carbide, alumina, cordierite, silicon nitride, aluminum nitride, or zirconia.
The heat exchanger according to the present invention is made of any one of silicon carbide, silicon-impregnated silicon carbide, alumina, cordierite, silicon nitride, aluminum nitride, or zirconia. Can be provided.

  According to the present invention, since the flow of the fluid can be drawn not only in the flow path formed by the inner wall of the honeycomb structure constituting the heat exchanger but also in the direction crossing the flow path, the conventional ceramic honeycomb structure New functions can be added that are not found in heat exchangers made of body. In addition, since the connection hole has a shape in which a portion where the fluid stagnates is difficult to be formed, heat can be exchanged efficiently.

It is the perspective view of the heat exchanger of 1st Embodiment which concerns on this invention, (a) is the perspective view seen from upper direction (1st side surface side), (b) is the perspective view seen from the downward direction (2nd side surface side). FIG. It is sectional drawing of the heat exchanger of 1st Embodiment which concerns on this invention, (a) is sectional drawing of the AA 'position in Fig.1 (a) and (b), (b) is FIG.1 (a). It is sectional drawing of the BB 'position in (b). (A), (b), (c) is explanatory drawing which shows the cutting position and cutting direction of FIG. 2 which are sectional drawings of FIG. 1 in detail. (A) And (b) is explanatory drawing which shows an example of the manufacturing method of the connection hole of the heat exchanger which concerns on this invention. It is explanatory drawing which shows another example of the manufacturing method of the connection hole of the heat exchanger which concerns on this invention. It is explanatory drawing which shows an example of the method of manufacturing the connection hole of the heat exchanger which concerns on this invention with a laser beam, (a) is the case where the light-transmitting stick | rod which has a curved surface in the flow path is inserted (B) shows the case where devitrified glass is inserted in the flow path, and (c) shows the case where water is put in the flow path. It is explanatory drawing which shows an example of the method of manufacturing the connection hole of the heat exchanger which consists of a honeycomb structure which concerns on this invention with the laser beam guide | induced by the water flow (water jet), (a) is a curved surface in a flow path (B) is a case where devitrified glass is inserted in the flow path, and (c) is a case where water is placed in the flow path. . (A) is the external appearance photograph of the heat exchanger which consists of a honeycomb structure of the Example which concerns on this invention, (b) is the explanatory drawing. It is a graph which shows the relationship between inclination-angle (theta) and heat exchange efficiency ratio. It is a graph which shows the relationship between inclination-angle (theta) and a pressure loss ratio.

In the present specification, the cross section of the honeycomb structure indicates a cross section cut in the depth direction of the connection hole along the flow path. For example, FIGS. 3A and 3B describe in detail the cutting position of FIG. 2, which is a cross-sectional view of FIG.
In the honeycomb structure of the heat exchanger of the present invention, the first flow path and the second flow path extend from the first end face toward the second end face. Moreover, the side surface of the honeycomb structure has a first side wall and a second side wall, and the second side wall is located opposite to the first side wall.

  The heat exchanger of the present invention is a heat exchanger composed of a ceramic honeycomb structure having at least a first end face, a second end face, a first side wall, and a second side wall, and the honeycomb structure is partitioned by an inner wall. A first channel having both ends extending from the first end surface to the second end surface sealed by a sealing portion, and a second channel having both ends opened, and the first channel. And in the heat exchanger configured such that the second flow paths constitute rows arranged from the first side wall toward the second side wall and are arranged alternately, the honeycomb structure The rectangular formed on the inner wall from the first opening formed on the first channel and the first end surface side of the first side wall and the second end surface side of the second side wall, respectively. And a pair of connection holes extending to the second opening 1 space and a second space composed of the first flow path and the second flow path separated by the inner wall, and the sealing of the first opening and the second opening. The pair of first imaginary lines connecting the midpoints of the short sides on the side far from the stop are straight lines parallel to each other, and the short sides on the side close to the sealing portion of the first opening and the second opening A pair of second imaginary lines connecting the midpoints are straight lines that are perpendicular to the first side wall and intersect the first imaginary line in the first side wall or the second side wall.

  According to the heat exchanger composed of the honeycomb structure of the present invention, unlike the conventional honeycomb structure in which the flow path extends in one direction, a fluid flow can be created in a direction crossing the honeycomb structure. Further, in such a honeycomb structure, since the first opening and the second opening are formed inside the first opening, not only the first flow channel located at the outermost periphery but also the inner first A fluid flow can also be created in one channel. In addition, since the second opening is formed at a position facing the first opening, the fluid can be moved with the first flow path inside the second opening in the shortest distance, and efficiently. A heat exchanger through which a fluid can flow can be provided.

In addition, since the heat exchanger of the present invention is made of ceramic and has heat resistance and corrosion resistance and high strength, it can handle a fluid even in a severe environment such as a high temperature environment or a corrosive environment.
Furthermore, in the heat exchanger according to the present invention, the first space has the sealing portions on the first end surface and the second end surface, respectively, so that the fluid from the first end surface and the second end surface side is in the first space. Intrusion can be prevented. Furthermore, since the first space is separated from the second space by the inner wall, the fluid flowing in the first space (first fluid) and the fluid flowing in the second space (second fluid) are in direct contact with each other. Absent. For this reason, functions, such as heat transfer and filtration, can be held in the inner wall.

  Since the heat exchanger of the present invention has a pair of connection holes in the first space, the pair of connection holes can serve as an inlet and an outlet for the fluid flowing in the first space. By providing an inlet and an outlet with a pair of connection holes in the first space, the fluid flowing in the first space (first fluid) can be used continuously.

  In addition, by having a pair of connection holes in the first space, there is an effect of increasing the amount of heat passing through the inner wall. The amount of heat passing through the inner wall that separates the first space and the second space is proportional to the temperature difference between the first space and the second space. By forming a flow from the inlet to the outlet in the fluid flowing through the first space, a new first fluid can be constantly supplied, and a temperature difference can be generated on the inner wall to increase the amount of heat that moves.

  The heat exchanger according to the present invention has the connection holes on the first and second side walls, respectively, so that the distance that the first fluid that connects the inlet and the outlet flows is equal regardless of the first flow path. can do. For this reason, since the 1st fluid can be spread over the whole inner wall, the heat exchanger which can perform heat transfer or mass transfer efficiently can be provided.

  In the heat exchanger according to the present invention, the first space and the second space face the first sidewall or the second sidewall alternately so that the flow in the direction crossing the flow path of the honeycomb structure is performed. They can be arranged in alternate flow paths. For this reason, the area of the inner wall that separates the fluid flowing along the second flow path (second fluid) and the first fluid flowing in the direction crossing the flow path (first fluid) can be increased.

  In the heat exchanger of the present invention, the shape of the first opening and the second opening is a rectangle that is long in the direction of the flow path. Since the opening is the first opening and the second opening, the fluid can be efficiently put in and out of the elongated channel while reducing the pressure loss.

  In the heat exchanger of the present invention, the pair of first imaginary lines connecting the midpoints of the short sides on the side far from the sealing portions of the first opening and the second opening are straight lines parallel to each other. A pair of second imaginary lines connecting the midpoints of the short sides of the opening and the second opening close to the sealing portion are perpendicular to the first side wall and the first side wall or the second side wall Since it is a straight line intersecting with one imaginary line, the cross section in the depth direction along the flow path of the connection hole formed by the first opening and the second opening is close to the sealing portion of the first opening. It becomes a right triangle with a right angle. The closer the connection hole is to the bottom, the narrower it becomes, so it is difficult to form a portion where the fluid stagnates at the bottom of the connection hole, so that the fluid can flow efficiently. In addition, since the pair of second imaginary lines connecting the midpoints of the short sides closer to the sealing portion of the first opening and the second opening are perpendicular to the first side wall, the connection hole is connected to the first end. 1st flow path which can be brought close to a part or a 2nd end part, and is hard to contribute to heat exchange with which a fluid does not flow easily can be made small.

Furthermore, the honeycomb structure of the present invention desirably has the following aspect.
(1) The inclination angle θ of the first imaginary line with respect to the first side wall or the second side wall is 35 degrees to 50 degrees.
When the inclination angle θ is 50 degrees or less, the pressure loss of the first fluid can be reduced, and when the inclination angle is 35 degrees or more, the length of the flow path can be increased and the heat exchange efficiency can be increased. Can be increased.

(2) The heat exchanger according to claim 2 or 2, wherein the connection hole is formed by stacking the second openings having five or more layers.
The heat exchanger of the present invention can supply the first fluid to the sixth flow path counted from the first side wall side by stacking the second openings of five layers or more. By adopting such a configuration, the area of the inner wall that separates the first space and the second space can be increased.

(3) In the connection hole, the second openings having ten or more layers are stacked.
The heat exchanger of the present invention can supply the first fluid to the eleventh channel counted from the first side wall side by stacking the second openings of 10 layers or more. With such a configuration, the area of the inner wall separating the first space and the second space can be further increased.

(4) The ceramic is made of silicon carbide, silicon-impregnated silicon carbide, alumina, cordierite, silicon nitride, aluminum nitride, or zirconia.
The heat exchanger according to the present invention is made of any one of silicon carbide, silicon-impregnated silicon carbide, alumina, cordierite, silicon nitride, aluminum nitride, or zirconia. Can be provided.

  The heat exchanger of the present invention can be obtained by forming connection holes in the first side wall or the second side wall of the honeycomb-shaped ceramic. It can be obtained by forming the first and second openings. Connection holes can be formed in the honeycomb-shaped ceramic on the first side wall or the second side wall by laser processing. The laser processing machine used for laser processing is not particularly limited. A honeycomb-shaped ceramic can be processed by using a widely used high-power laser beam. The wavelength and output of the laser beam of the laser processing machine can be appropriately selected according to the honeycomb ceramic.

  Further, it is possible to perform processing more efficiently by using a laser processing machine combined with a water flow of a water jet that has recently been used. The laser processing method combined with the water jet water flow guides the laser light into the water jet water flow and can guide it to the processing point while totally reflecting it, so that the laser light passes through a thin water flow without diffusing. The depth of focus is deep, and it has higher processing performance than a processing machine using only laser light.

The heat exchanger of the present invention can be obtained by processing without penetrating the bottom of the connection hole by using a laser processing machine combined with a water flow of a high processing performance water jet.
Processing while leaving the bottom of the connection hole can be realized by scattering laser light at a predetermined location and dispersing light energy. By inserting the light diffusing medium at a predetermined location, the laser light is weakened below and cannot be processed. The light diffusion medium is not particularly limited as long as light can be dispersed. For example, a light-transmitting rod having a curved surface such as a glass rod, devitrified glass, glass having bubbles inside, water, and the like can be used. A light-transmitting substance is not heated by laser light, and light is scattered on a curved surface, so that the ability to process laser light can be reduced, and the bottom of the connection hole can be formed without penetrating. Can be processed.

  In addition, devitrified glass has a phase-separated interior even if the surface is not curved, so that light is easily scattered, the ability to process laser light can be reduced, and the bottom is formed without penetrating. be able to. Moreover, it can process by leaving the bottom of a connection hole by filling water in a predetermined location. When filled with water, a large amount of bubbles are generated by boiling water heated by mixing and processing with a water jet stream. For this reason, the laser beam is rapidly attenuated in the filled water, and processing can be performed while leaving the bottom of the connection hole. Even when water is not filled, water is supplied by the water flow along with the laser light, but the amount of water used for the water flow is small and the laser light scatters quickly near the place where the ceramic is processed (processing point). As the laser beam is weakened, bubbles cannot be formed in the section.

  The heat exchanger of the present invention has various modifications of the connection holes, but can be processed by tilting or scanning the laser beam according to the shape.

Further, when processing while scanning with laser light, the connection hole having a desired shape can be formed by appropriately changing the length of the light diffusion medium inserted into each flow path.
The sealing part of the heat exchanger of the present invention may be formed in any way and is not particularly limited. For example, a plug made of the same ceramic material as that constituting the inner wall may be inserted. For example, when the honeycomb structure is made of silicon carbide, silicon nitride, or silicon carbide impregnated with silicon, silicon powder may be applied to the plug as an adhesive and then fired. Silicon melts and functions as an adhesive.
Further, for example, it can be obtained by injecting and baking a paste in which an inorganic binder, an organic binder, and inorganic particles are mixed. As the inorganic binder, alumina sol, silica sol or the like can be used. As the organic binder, polyvinyl alcohol, phenol resin or the like can be used. As the inorganic particles, silicon carbide, alumina, cordierite, silicon nitride, aluminum nitride, zirconia or the like can be used.

Next, a first embodiment of the present invention will be described. The first embodiment is a heat exchanger having the following configuration.
<First Embodiment>
A connection hole including a first opening and a second opening is provided on one end face side of the first end face and the second end face in the first side wall and on the other end face side in the second side wall. The first opening is a rectangular opening provided in a slit shape from the sealing portion toward the inside in the longitudinal direction. The first opening is longer than the second opening, and the connection holes are provided so that the plurality of second openings become longer in order toward the first opening. At this time, the bottom of the connection hole reaches the first side wall or the second side wall.
Thus, the pair of first imaginary lines connecting the midpoints of the short sides on the side far from the sealing portion of the first opening and the second opening are straight lines parallel to each other, and the first opening and the second opening The pair of second imaginary lines connecting the midpoints of the short sides on the side close to the sealing portion of the opening is perpendicular to the first side wall and is connected to the first imaginary line in the first side wall or the second side wall. Arranged to be intersecting straight lines.

The heat exchanger of 1st Embodiment is demonstrated using a figure.
FIG. 1A is a perspective view of the heat exchanger according to the first embodiment of the present invention viewed from above (first side wall side), and FIG. 1B is a perspective view of the heat exchanger viewed from below (second side wall side). It is. 2A is a cross-sectional view taken along the line AA ′ in FIGS. 1A and 1B, and FIG. 2B is a cross-sectional view taken along the line BB ′ in FIGS. 1A and 1B. FIG. FIG. 9 is a graph showing the relationship between the inclination angle and the heat exchange efficiency ratio. FIG. 10 is a graph showing the relationship between the tilt angle and the pressure loss ratio. In both cases, the deviation is displayed in% with reference to the value at an inclination angle of 45 °.

As shown in FIGS. 1A and 1B, a first opening 31 is formed on one end face side of the first end face 11 and the second end face 12 on the first side wall 21 and on the other end face side of the second side wall 22. Provide each.
For example, the first opening 31 of the connection hole 30 is provided at the first end surface 11 side end portion of the first side wall 21, and the first end of the connection hole 30 is also provided at the second end surface 12 side end portion of the second side wall 22. An opening 31 is provided.
In the heat exchanger (1000), for example, 64 flow paths 60 of 8 columns × 8 rows are provided, and the first end surface 11 from the left side in FIG. A sealing portion 70 is provided in the seventh row. Similarly, in the second end surface 12, the sealing portions 70 are provided in the first row, the third row, the fifth row, and the seventh row.

As shown in FIG. 2A, the connection holes 30 provided in the first side wall 21 and the second side wall 22 are located in a row where the sealing portion 70 is provided.
The first opening 31 is a rectangular opening provided in a slit shape on the inner side in the longitudinal direction from the sealing portion 70. The first opening 31 is longer than the second opening 32, and the plurality of second openings 32 are provided so as to become longer in order toward the first opening 31. At this time, the bottom of the connection hole 30 reaches the first side wall 21 or the second side wall 22.

  As a result, the pair of first imaginary lines connecting the midpoints of the short sides of the first opening 31 and the second opening 32 on the side far from the sealing portion 70 are straight lines parallel to each other. A pair of second imaginary lines that connect the midpoints of the short sides of the second opening 32 closer to the sealing portion 70 are perpendicular to the first side wall 21 and the first side wall 21 or the second side wall 22. It arrange | positions so that it may be a straight line which cross | intersects a 1st virtual line.

Therefore, the crank-shaped first space 41 is formed by the triangular prism-shaped region R1 (R) on the first end surface 11 side, the flow path 60, and the triangular region R2 (R) on the second end surface 12 side. As a result, the fluid flows in a crank shape through the first space 41.
Here, an angle formed by the first imaginary line with respect to the first side wall 21 or the second side wall 22 is referred to as an inclination angle θ. As will be described later, the inclination angle θ is desirably 35 to 50 degrees. Since the honeycomb structure is a rectangular parallelepiped, the first side wall 21 and the second side wall 22 are parallel.

In the cross section in which the connection hole 30 is not provided, the second space 42 is formed by the plurality of flow paths 60 as shown in FIG.
In the second space 42, the flow path 60 is open at the first end surface 11 and the second end surface 12, and the fluid flowing through the second space 42 flows linearly.

FIG. 9 shows a graph showing the relationship between the inclination angle θ and the heat exchange efficiency ratio. In FIG. 9, a honeycomb structure 1000 (heat exchanger) of 50 mm × 50 mm, length of 210 mm, 10 mil, and 300 cpsi is targeted. Further, the horizontal axis represents the inclination angle θ (degrees), and the vertical axis represents the heat exchange efficiency ratio. With respect to the heat exchange efficiency ratio, the deviation is expressed in% on the basis of the heat exchange efficiency when the inclination angle is 45 °.
FIG. 10 is a graph showing the relationship between the inclination angle θ and the pressure loss ratio. In FIG. 9, a honeycomb structure 1000 (heat exchanger) of 50 mm × 50 mm, length of 210 mm, 10 mil, and 300 cpsi is targeted. Further, the horizontal axis represents the inclination angle θ (degrees), and the vertical axis represents the pressure loss ratio. With respect to the pressure loss ratio, the deviation is expressed in% on the basis of the pressure loss when the inclination angle is 45 °.

  The condition at this time assumes a condition in which the fluid flows as a laminar flow. For this reason, as long as the fluid flows as a laminar flow, this tendency does not change, and the peak position and the sign of the slope do not change. In the heat exchanger having the configuration according to the present invention, if the Reynolds number in the flow path is 2300 or less, the fluid can flow as a laminar flow.

As shown in FIGS. 9 and 10, when the inclination angle θ is 20 degrees, the pressure loss is small but the heat exchange efficiency is low as compared with the case where the inclination angle θ is 35 degrees to 50 degrees. Further, when the inclination angle θ is 60 degrees, the pressure loss is large and the heat exchange efficiency is low as compared with the case where the inclination angle θ is 35 degrees to 50 degrees.
From the above results, the inclination angle θ is desirably 35 degrees to 50 degrees. Furthermore, the inclination angle θ is more preferably 40 to 45 degrees.

Next, a method for forming the first space 41 will be described. In FIG. 2A, the left triangular prism-shaped region R1 and the right region R2 are considered to be point-symmetric with respect to the center of the honeycomb structure 1000 (heat exchanger), and thus are processed by the same method. be able to. Accordingly, the left region R1 will be described.
For the formation of the region R1, the formation method shown in FIGS. 4A, 4B or 5 can be used. That is, as shown in FIGS. 4A and 4B, the light diffusion medium 90 is inserted into the first flow path and processed using laser light, as shown in FIG. The connection hole 30 having a triangular prism shape can be obtained by appropriately changing the insertion length. Alternatively, the triangular prism-shaped connection hole 30 can be obtained by scanning the laser beam 80 while appropriately tilting it.

As a method of forming the region R1 by blocking the laser beam 80 using the light diffusion medium 90, the following can be applied.
6A and 7A show a case where a glass rod 91 is used as the light diffusion medium 90, and the laser light 80 can be blocked by the diffusion of the laser light 80 by the convex surface of the glass.
FIGS. 6B and 7B are explanatory diagrams in which a devitrifying glass 92 is used for the light diffusion medium 90. The laser light 80 can be diffused and blocked by the irregular reflection inside the glass. .
FIGS. 6C and 7C are explanatory diagrams in which water 93 is used for the light diffusing medium 90, and the laser light 80 is diffused by the diffuse reflection of bubbles generated by the turbulent flow of heat and water by processing. The light 80 can be blocked.

The honeycomb structure (heat exchanger) 1000 of the present embodiment can draw the fluid flow in the direction crossing the flow path 60 by forming the first space 41 in a crank shape.
Thereby, a new function not provided in the heat exchanger made of the conventional ceramic honeycomb structure can be provided. Further, since the connection hole 30 has a shape in which a portion where the fluid stagnates is difficult to be formed, heat exchange can be performed efficiently.

In this example, the result of manufacturing the honeycomb structure (heat exchanger) 1000 according to the present invention by forming the connection hole 30 having a trapezoidal cross section in the honeycomb-shaped ceramic actually made of porous silicon carbide, This will be described with reference to FIGS.
A honeycomb structure 1000 (heat exchanger) according to the present invention is formed using a honeycomb-shaped ceramic made of silicon carbide of 34 mm × 34 mm × 130 mm, having 24 × 24, a total of 576 square flow paths 60. Produced. The end face in the longitudinal direction has an opening of the flow path 60 and is the first end face 11 and the second end face 12. The four surfaces other than the first end surface 11 and the second end surface 12 are side walls, of which the surface forming the connection hole 30 is the first side wall 21, and the opposite surface is the second side wall 22. The inner wall 50 has a thickness of 0.25 mm, and the first side wall 21 and the second side wall 22 have a thickness of 0.3 mm. The size of the flow path is a square having a side of 1.14 mm.

  As shown in FIGS. 8A and 8B, connection holes 30 were formed in the honeycomb-shaped ceramic. By forming the first openings 31 in the twelve channels 60 out of the twenty-four channels 60 facing the first side wall 21 and further forming the second openings 32, 12 The connection hole 30 was formed. The bottom of the connection hole 30 is the second side wall 22, and the second openings 32 are formed in all the inner walls 50. The distance between the first opening 31 and the second opening 32 and the first end surface 11 is 10 mm, and the first opening 31 extends from the first end surface 11 to a position of 40 mm. The second opening 32 becomes longer in the order toward the first opening 31, and the cross section of the connection hole 30 is a right triangle having a hypotenuse on the center side in the direction of the flow path of the honeycomb structure. The width of the first opening 31 is 0.6 mm.

A detailed processing method will be described below. When forming the connection hole 30, a circular glass rod 91 longer than the flow path 60 is inserted into the flow path 60 facing the second side wall 22, and the other flow paths 60 have portions other than the trapezoidal basin. A circular glass rod 91 was inserted up to.
Next, it processed using the MCS300 type | mold laser processing machine by Makino milling company along the flow path 60 which faces the 1st side wall 21. FIG. Processing was performed at a laser wavelength of 532 nm, an output of 80 W, a nozzle diameter of the water flow 82 of φ80 μm, and a scanning speed of 300 mm / min.

The honeycomb structure 1000 (heat exchanger) obtained by processing in this way was cut along the connection holes 30 to confirm the connection holes 30. As shown in FIG. 2A, the connection hole 30 has a trapezoidal cross section, the entire inner wall 50 penetrates, the first opening 31 has a length of 30 mm, and the lowermost second opening 32 has a length of 15 mm. It was.
Thus, it was confirmed that the connection hole 30 could be formed with a laser processing machine using the water flow 82. The method of forming the connection hole 30 in the honeycomb structure 1000 (heat exchanger) is not limited to the laser beam using the water flow 82. If the laser processing machine takes a long time and has a high output, the water flow 82 is used in combination. Can be processed without any problems.

  Further, the size, arrangement, and number of the connection holes 30 can be selected as appropriate.

  The heat exchanger of the present invention can be used as a heat exchanger for an internal combustion engine, a combustion furnace, or the like.

11 1st end surface 12 2nd end surface 21 1st side wall 22 2nd side wall 30 Connection hole 31 1st opening 32 2nd opening 41 1st space 42 2nd space 50 Inner wall 60 Flow path 70 Sealing part 80 Laser Light 82 water stream (water jet)
85 Laser source 90 Light diffusion medium 91 Glass rod 92 Devitrified glass 93 Water 1000 Honeycomb structure (heat exchanger)
P Intersection R region θ Inclination angle

Claims (5)

A heat exchanger comprising a ceramic honeycomb structure having at least a first end face, a second end face, a first side wall, and a second side wall, wherein the honeycomb structure is partitioned by an inner wall and the first end face is separated from the first end face. A first channel having both ends extending to the two end faces sealed by a sealing portion; and a second channel having both ends opened, wherein the first channel and the second channel are In each of the heat exchangers that are arranged in rows arranged alternately from the first side wall toward the second side wall,
The honeycomb structure is
A rectangular first formed on the inner wall from the first flow path and a first rectangular opening formed on the first end surface side of the first side wall and the second end surface side of the second side wall, respectively. A first space comprising a pair of connection holes extending to the two openings;
A second space composed of the first flow path and the second flow path separated by the inner wall;
Have
A pair of first imaginary lines connecting the midpoints of the short sides of the first opening and the second opening on the side far from the sealing portion are straight lines parallel to each other, and the first opening and the second opening A pair of second imaginary lines connecting the midpoints of the short sides of the two openings close to the sealing portion are perpendicular to the first side wall and the first side wall or the second side wall A heat exchanger characterized by being a straight line intersecting the first imaginary line.   2. The heat exchanger according to claim 1, wherein an inclination angle θ of the first imaginary line with respect to the first side wall or the second side wall is 35 degrees to 50 degrees.   The heat exchanger according to claim 1 or 2, wherein the connection hole is formed by stacking the second openings having five or more layers.   4. The heat exchanger according to claim 3, wherein the connection hole is formed by stacking the second openings of ten layers or more.   5. The ceramic according to claim 1, wherein the ceramic is made of any one of silicon carbide, silicon-impregnated silicon carbide, alumina, cordierite, silicon nitride, aluminum nitride, or zirconia. Heat exchanger.